diff --git a/cmd/icingadb/main.go b/cmd/icingadb/main.go
index bd94686d7..66ad0debc 100644
--- a/cmd/icingadb/main.go
+++ b/cmd/icingadb/main.go
@@ -109,6 +109,7 @@ func run() int {
 		heartbeat = icingaredis.NewHeartbeat(ctx, rc, logs.GetChildLogger("heartbeat"))
 
 		db, err := cmd.Database(logs.GetChildLogger("database"))
+		db.SetMaxOpenConns(1)
 		if err != nil {
 			logger.Fatalf("%+v", errors.Wrap(err, "can't create database connection pool from config"))
 		}
diff --git a/doc/03-Configuration.md b/doc/03-Configuration.md
index 472389483..14ac1d5ef 100644
--- a/doc/03-Configuration.md
+++ b/doc/03-Configuration.md
@@ -63,6 +63,12 @@ do not need any manual adjustments.
 | max_rows_per_transaction       | **Optional.** Maximum number of rows Icinga DB is allowed to `SELECT`,`DELETE`,`UPDATE` or `INSERT` in a single transaction. Defaults to `8192`. |
 | wsrep_sync_wait                | **Optional.** Enforce [Galera cluster](#galera-cluster) nodes to perform strict cluster-wide causality checks. Defaults to `7`.                  |
 
+!!! info
+
+    The [Icinga DB HA](05-Distributed-Setups.md#high-availability) feature uses its own database connection, separate
+    from the other Icinga DB components, and this configuration cannot be altered by end users. Therefore, expect
+    Icinga DB to establish `max_connections` + `1` database connections.
+
 ## Logging Configuration
 
 Configuration of the logging component used by Icinga DB.